Pure silicon does not exist in nature. Various methods can be used to remove the impurities from silicon ore. Some methods involve heating and melting the silicon so that impurities are driven out of the molten silicon by outgassing or sedimentation. Outgassing is enhanced in a controlled vacuum environment. Methods of heating and melting silicon ore must take into consideration the fact that silicon is essentially non-electrically conductive in the solid state, and electrically conductive in the molten state.
It is one object of the present invention to provide a method of purifying silicon by heating and melting a charge of impure solid silicon in a controlled environment by inductively heating multiple susceptor elements surrounding a crucible containing solid silicon.